Vision improving device

ABSTRACT

A vision training device includes a housing having at least one eyepiece unit corresponding to an eye of a user, a display that displays a target image in front of a fixation axis of the user, a lens arranged between the eyepiece unit and the display unit, a movable unit capable of moving at least one of the display and the lens along the fixation axis, and a control unit that sets at least one training range within a movable range of the display and the lens and controls the movable unit such that at least one of the display and the lens is moved within the training range.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of PCT/KR2017/011094,which was filed on Oct. 2, 2017 which claims priority toPCT/KR2016/014739, which was filed on Dec. 15, 2016 and to U.S.application Ser. No. 15/281,530, which was filed on Sep. 30, 2016. Theentire contents of each of which are incorporated herein in theirentirety.

BACKGROUND

The present disclosure relates to a vision training device that trainsmuscles of the eyes on the basis of a status of personal vision of auser.

Human vision may be associated with a ciliary muscle of the eye. Thus,human vision can be improved or maintained by training of contracting orrelaxing the ciliary muscle. However, since an individual human'sciliary muscle has varying abilities, vision training may be customizedcorresponding to each individual's vision.

However, training the ciliary muscle by simply changing a focal lengthof the eye of the user without considering the status of personal visionhas a low training efficiency and is not easy for the user to adapt to.An improved vision training device would be desirable.

BRIEF SUMMARY

According to an aspect, a vision training device has a relatively hightraining efficiency for the ciliary muscle.

A vision training device may include a housing having at least oneeyepiece unit corresponding to an eye of a user, a display that displaysa target image in front of a fixation axis of the user, a lens arrangedbetween the eyepiece unit and the display unit, a movable unit capableof moving at least one of the display and the lens along the fixationaxis, and a control unit that sets at least one training range (TR)within a movable range of the display and the lens and controls themovable unit such that at least one of the display and the lens is movedwithin the training range.

The control unit may set an accommodation range corresponding to a rangebetween a predetermined near point of accommodation position and a farpoint of accommodation position within the movable range, and thetraining range includes the accommodation range.

A user input unit may receive a user input signal from the user, and thenear point of accommodation position and the far point of accommodationposition may be set through an input of the user input signal.

A sensor module may check if the eye of the user transitions from anaccommodated state to a non-accommodated state or transitions from thenon-accommodated state to the accommodated state and generate anaccommodation state change confirmation signal is further included, andthe control unit sets the near point of accommodation position and thefar point of accommodation position on the basis of the accommodationstate change confirmation signal.

The control unit may measure a continuous or intermittent accommodationspeed through the user input unit or the sensor module within theaccommodation range, and the training speed in the training range of thedisplay and the lens is determined by reflecting the measured speed.

The control unit may set a predetermined point of accommodation positionand a far point of accommodation position within the accommodationrange, and the training range includes at least a part of a fastaccommodation range between the near point of accommodation position andthe far point of accommodation position.

In an example, at least one second lens is arranged between the lens andthe display along the fixation axis or between the lens and the eyepieceunit.

The movable unit may include a second movable unit that moves the secondlens, and the second movable unit is any one of a piezo actuator, a VCMactuator, and an encoder actuator.

The movable unit may selectively move at least one of the lens and thesecond lens.

An image size of the target image may vary depending on a position ofthe display.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an exemplary vision trainingdevice.

FIG. 2 is a control block diagram of an exemplary vision trainingdevice.

FIGS. 3A, 3B, 3C, 3D are diagrams illustrating various exemplary methodsof measuring a near point of accommodation position and a far point ofaccommodation position in a vision training device.

FIG. 4 is a diagram describing exemplary measurement and trainingprocesses based on display movement.

FIG. 5 is a flowchart illustrating an exemplary process of measuring anear point of accommodation position and a far point of accommodationposition using a measurement method such as illustrated in (A) of FIG. 3.

FIG. 6 is a flowchart illustrating an exemplary training mode process ina vision training device.

FIG. 7 is a sequence diagram illustrating an exemplary training modeprocess in a vision training device.

FIG. 8 is a diagram illustrating a training method according to anexample illustrated in FIG. 7 .

FIG. 9 is a reference diagram describing an exemplary training processbased on lens movement.

FIG. 10 is a diagram schematically illustrating an exemplary visiontraining device including a plurality of lenses.

DETAILED DESCRIPTION

Various aspects of a vision training device and related methodsaccording to the present disclosure are described. It is to beunderstood, however, that the following explanation is merely exemplaryin describing the devices and methods of the present disclosure.Accordingly, any number of reasonable and foreseeable modifications,changes, and/or substitutions are contemplated without departing fromthe spirit and scope of the present disclosure.

In an exemplary vision training device, training the ciliary muscle isperformed in consideration of the status of personal vision of the user,and thus the training efficiency is high, and the vision recovery effectis high as well.

FIG. 1 is a perspective view illustrating an exemplary vision trainingdevice. As illustrated in FIG. 1 , a vision training device includes ahousing 110 indicated by a two-dot chain line and a pair of visiontraining units 120 arranged side by side in the housing 110. The housing110 includes a shielding plate 122 which is arranged between the pair ofvision training units 120 and shields the visual fields of the left andright eyes from each other. In some embodiments, the vision trainingunits 120 may respectively have separate housing structures and theshielding plate 122 may be provided by part of the respective housingsof the vision training units or omitted.

The housing 110 includes a pair of eyepiece units 124 corresponding toboth eyes of the user, and the user can view the inside of the housing110 through the eyepiece units 124. The pair of eyepiece units 124 maybe connected without a shielding partition so that a through hole isformed. A user input unit 160 may receive a signal in accordance with amanipulation of the user and is installed on the upper surface of thehousing 110. It will be appreciated that the user input 160 may beprovided on other surfaces of the housing or as a remote unit. The usercan input information or select a training condition such as a traininglevel such as a slow accommodation range (SAR) and a fast accommodationrange (FAR) to be described later, a training mode such as a trainingperiod, or the like through the user input unit 160. The housing 110 mayinclude a strap or a device made of a material with elasticity to fixthe housing 110 on the head of the user.

The vision training unit 120 includes displays 130 and lenses 140, whichare respectively arranged to face each other along a fixation axis. Thevision training unit 120 includes lens holders 142 that hold the lenses140. Each of the lens holders 142 is arranged corresponding to thecorresponding eyepiece unit 124. The user can see the displays 130through the lenses 140 supported by the lens holders 142.

The display 130 displays a target image for vision training. The display130 may be an electronic display device such as an LCD or an LED or astatic display item such as paper, a plastic plate, or the like. Thetarget image can be a static image such as a landscape, a graphic, apoint, or a geometric shape or a moving picture.

The lens 140 is mounted on the lens holder 142 and arranged between theeyepiece unit 124 and the display 130. The user can view the targetimage displayed on the display 130 through the eyepiece unit 124 and thelens 140. The lens 140 is preferably a convex lens. The convex lens canextend the perspective of an image by changing the focal length betweenthe eye of the user and the target image so that the user recognizes theimage as if the image were at a distance farther than an actualdistance. The lens 140 is not limited to a convex lens, and varioustypes of lenses such as a polarizing lens, a color lens, and the likecan be employed. In a case in which a polarizing lens or a color lens isemployed, the user can view the target image which is partiallyfiltered, e.g., partially recognized.

The display 130 and the lens holder 142 are connected by a movable unit150. The movable unit 150 includes a lead screw 151, a movable body 152,and a drive motor unit 153. The movable body 152 may be coupled to thedisplay 130, and the drive motor unit 153 may be coupled to the lensholder 142, or vice versa. The lead screw 151 connects the drive motor153 with the movable body 152.

As the drive motor 153 is driven, the lead screw 151 rotates, and thedisplay 130 and the lens 140 is moved toward or away from each otheralong the fixation axis. In a case in which the display 130 is fixed tothe housing 110, the lens 140 is moved relative to the display 130 asthe drive motor 153 is driven. In a case in which the lens holder 142 isfixed to the housing 110, the display 130 is moved relative to the lens140 as the drive motor 153 is driven. The display 130 and the lensholder 142 may be configured to move relative to the housing 110 so thatthe display 130 and the lens 140 can be moved independently at the sametime. A manual driving method in which the display 130 and the lens 140are moved by a manipulation of the user may also be employed.

FIG. 2 is a control block diagram for an exemplary vision trainingdevice. Referring to FIGS. 1 and 2 , the vision training device includesa control unit 190, which may include a processor to execute thefunctions described herein, that receives information input from theuser input unit 160, which includes a plurality of user input buttons161 to 166. The user input unit 160 may include a power button, a userselection button, a forward moving button, a backward moving button, ameasurement mode button, and a training mode button. The user input unit160 may be provided by a wired or wireless remote controller or mayreceive information using voice recognition, a gyro sensor, or an eyetracking technique using an image recognition sensor.

The vision training device may include a communication unit 170 thatprovides wired or wireless communication with an external device such asa smart phone, a tablet, a PC, or a user server. The communication unit170 can perform transmission and reception of data generated in thevision training device with the external device.

The vision training device may include a memory 180 that stores userinformation, diopter conversion data, vision data, training data, andvarious types of data necessary for the operation of the vision trainingdevice. The diopter conversion data includes data obtained by convertinga position of the display 130 and the lens 140 into a diopter valuewithin a movable range of the display 130 or the lens 140.

The control unit 190 can control at least one of the pair of displays130 and the pair of lenses 140 individually. Accordingly, in theexemplary vision training device, it is possible to freely select andtrain either of the left eye and the right eye or both the left eye andthe right eye.

FIG. 3 is an explanatory diagram illustrating various methods ofmeasuring a near point of accommodation position P5 and a far point ofaccommodation position P6 in the exemplary vision training device. FIG.4 is a reference diagram for describing measurement and trainingprocesses based on display movement. FIG. 5 is a flowchart illustratinga process of measuring or setting the near point of accommodationposition P5 and the far point of accommodation position P6 using ameasurement method illustrated in (A) of FIG. 3 . Referring to FIGS. 3,4, and 5 , the near point of accommodation position P5 and the far pointof accommodation position P6 can be measured or set while the display130 or the lens 140 is being moved from a far position P2 to a nearposition P1 as illustrated in (A) of FIG. 3 .

An exemplary process of operating the vision training device will now bediscussed. The user may press the power button of the user input unit160 so that the device is powered on. The user wears the vision trainingdevice and selects a measurement mode by pressing the measurement modeselection button of the user input unit 160 (S110).

When the measurement mode is selected by the user, the control unit 190controls the drive motor 153 such that the display 130 or the lens 140is moved to the far position P2 (S120). The far position P2 is thefarthest position from the eyepiece unit 124 in a movable range MR ofthe display 130 or the lens 140 and can be adjusted within apredetermined range.

The control unit 190 controls the drive motor 153 such that the display130 or the lens 140 is continuously or intermittently moved from the farposition P2 toward the eyepiece unit 124 (step S130). The moving speedin the case of continuous moving or the intermittent moving interval inthe case of the intermittent moving can be adjusted to a set speed or aset interval.

The control unit 190 checks whether or not an accommodation reflexconfirmation signal is input from the user input unit 160 (S140). Theaccommodation reflex confirmation signal is a signal which is generatedand transmitted to the control unit 190 in accordance with amanipulation of the user on the user input unit 160 when the eye of theuser transitions from a non-accommodated state to an accommodated state.When a target image TI which is blurred transitions to be seen clearlyas the display 130 or the lens 140 is moved, that is, at a point atwhich the visibility of the target image TI by the user changes, theuser presses the user selection button of the user input unit 160, sothat the accommodation reflex confirmation signal is input.

When the accommodation reflex confirmation signal is input from the userinput unit 160, the control unit 190 stores a position of the display130 or the lens 140 as the far point of accommodation position P6(S150).

The control unit 190 controls the drive motor 153 such that the display130 or the lens 140 is moved toward the eyepiece unit 124 continuouslyor intermittently (S160). A moving speed in the case of the continuousmoving or a waiting time in a non-moving state in the case of theintermittent moving can be adjusted.

The control unit 190 checks whether or not a non-accommodation stateconfirmation signal is input from the user input unit 160 (S170). Thenon-accommodation state confirmation signal is a signal which isgenerated and transmitted to the control unit 190 in accordance with amanipulation of the user on the user input unit 160 when the eye of theuser transitions from the accommodated state to the non-accommodatedstate. When the target image TI which is clear transitions to be seenblurred as the display 130 or the lens 140 is moved, that is, at a pointat which the visibility of the target image TI by the user changes, theuser presses the user selection button of the user input unit 160, sothat the non-accommodation state confirmation signal is input.

When the non-accommodation state confirmation signal is input from theuser input unit 160, the control unit 190 stores a position of thedisplay 130 or the lens 140 as the near point of accommodation positionP5 (S180). The far point of accommodation position P6 and the near pointof accommodation position P5 are individually measurable.

It will be appreciated that the far point of accommodation position P6and the near point of accommodation position P5 can be measured by othermethods and the method of moving from the far position (P2) to the nearposition (P1) is exemplary in nature.

The near point of accommodation position P5 and the far point ofaccommodation position P6 can be measured while the display 130 or thelens 140 is being moved from the near position (P1) to the far position(P2) as illustrated in (B) of FIG. 3 .

The control unit 190 controls the drive motor 153 such that the display130 or the lens 140 is moved to the near position P1. Preferably, thenear position P1 is a position which is closest to the eyepiece unit 124in the movable range of the display 130 or a position which is apartfrom the eyepiece unit 124 by a predetermined distance.

After the display 130 or the lens 140 is moved to the near position P1,the control unit 190 controls the drive motor 153 such that the display130 or the lens 140 is continuously or intermittently moved in adirection from the eyepiece unit 124 toward the far point P2. The movingspeed in the case of the continuous moving or the waiting time in thenon-moving state in the case of the intermittent moving can be adjusted.

The control unit 190 checks whether or not the accommodation reflexconfirmation signal is input from the user input unit 160. When thetarget image TI which is blurred transitions to be seen clearly as thedisplay 130 or the lens 140 is moved, that is, at a point at which thevisibility of the target image TI by the user changes, the user pressesthe user selection button of the user input unit 160, so that theaccommodation reflex confirmation signal is input. The control unit 190stores the position of the display 130 or the lens 140 as the near pointof accommodation position P5 at a time point at which the accommodationreflex confirmation signal is input from the user input unit 160.

The control unit 190 controls the drive motor 153 such that the display130 or the lens 140 is continuously or intermittently moved toward thefar position P2. The moving speed in the case of the continuous movingor the waiting time in the case of the intermittent moving can beadjusted.

The control unit 190 checks whether or not the non-accommodation stateconfirmation signal is input from the user input unit 160. When thetarget image TI which is clear transitions to be seen blurred as thedisplay 130 or the lens 140 is moved, that is, at a point at which thevisibility of the target image TI by the user changes, the user pressesthe user selection button of the user input unit 160, so that thenon-accommodation state confirmation signal is input. When thenon-accommodation state confirmation signal is input from the user inputunit 160, the control unit 190 stores the position of the display 130 orthe lens 140 as the far point of accommodation position P6. The nearpoint of accommodation P5 and the far point of accommodation P6 need notbe continuously measured, and any one of the near point of accommodationP5 and the far point of accommodation P6 may be measured.

The near point of accommodation position P5 and the far point ofaccommodation position P6 may be measured while the display 130 or thelens 140 is being moved with reference to a user reference position.

A middle point of a statistically average accommodation range at theuser's age may be set as the user reference position, or a position atwhich the user can see most comfortably when the display 130 or the lens140 is moved forward or backward at a predetermined speed within theline of sight range may be set as the user reference position inaccordance with the input from the user. The near point of accommodationposition P5 may be set on the basis of the signal input from the userinput unit 160 when the transition from the accommodated state to thenon-accommodated states is performed while the display 130 or the lens140 is being moved toward the eyepiece unit 124. The far point ofaccommodation position P6 may be set while the display 130 or the lens140 is being moved in the opposite direction.

As illustrated in (D) of FIG. 3 , the near point of accommodationposition P5 may be decided while the display 130 or the lens 140 isbeing moved from the far position P2 to the near position P1, and thenthe far point of accommodation position P6 may be decided while thedisplay 130 or the lens 140 is being moved from the near position P1 tothe far position P2.

In a case in which the display 130 or the lens 140 is moved from the farposition P2 to the near position P1, the transition from thenon-accommodated state to the accommodated state and the transition fromthe accommodated state to the non-accommodated state are performed. Inthe measurement method illustrated in (D) of FIG. 3 , when thetransition from the accommodated state to the non-accommodated state isperformed, the near point of accommodation position P5 is decided on thebasis of the signal input from the user input unit.

When the display 130 or the lens 140 is moved from the near position P1to the far position P2, the transition from the non-accommodated stateto the accommodated state and the transition from the accommodated stateto the non-accommodated state are performed. In the measurement methodillustrated in (D) of FIG. 3 , when the transition from the accommodatedstate to the non-accommodated state is performed, the far point ofaccommodation position P6 is decided on the basis of the signal inputfrom the user input unit. At this time, preferably, the near point ofaccommodation position P5 and the far point of accommodation position P6are repeatedly measured while reducing the moving speed of the display130 or the lens 140, and converged positions are selected as the nearpoint of accommodation position P5 and the far point of accommodationposition P6.

The near point of accommodation position P5 and the far point ofaccommodation position P6 can be decided by various methods other thanthe above-described methods. For example, the near point ofaccommodation position P5 and the far point of accommodation position P6may be measured while the display 130 or the lens 140 is being movedcontinuously from the far position P2 to the near position P1 or fromthe near position P1 to the far position P2. When the moving speed ofthe display 130 or the lens 140 is different, positions measured as thenear point of accommodation position P5 and the far point ofaccommodation position P6 may be different. As the moving speed of thedisplay 130 or the lens 140 increases, the width between the near pointof accommodation position P5 and the far point of accommodation positionP6, which are measured, may decrease, whereas as the moving speed of thedisplay 130 or the lens 140 decreases, the width between the near pointof accommodation position P5 and the far point of accommodation positionP6, which are measured, may increase.

In some examples, one of a plurality of near point of accommodationpositions P5 and one of a plurality of far point of accommodationpositions P6 measured by various methods as described above may beselected. For example, the position measured by the method described in(B) of FIG. 3 may be selected as the near point of accommodationposition P5, and the position measured by the method described in (A) ofFIG. 3 may be selected as the far point of accommodation position P6.

The near point of accommodation positions P5 and the far point ofaccommodation positions P6 measured in the methods illustrated in (A) to(D) of FIG. 3 may be slightly different in position. The near point ofaccommodation position P5 measured by the method illustrated in (B) ofFIG. 3 may be desirable as the near point of accommodation position P5,and the far point of accommodation position P6 measured by the methodillustrated in (A) of FIG. 3 may be desirable as the far point ofaccommodation position P6, but the near point of accommodation positionP5 and the far point of accommodation position P6 measured by themethods illustrated in (C) and (D) of FIG. 3 may be selected.

To determine the near point of accommodation position P5 and the farpoint of accommodation position P6 which are reliable, it is desirablefor the user to perform the above-described measurement procedurerepeatedly and decide an average near point of accommodation position P5and an average far point of accommodation position P6 as the near pointof accommodation position P5 and the far point of accommodation positionP6.

The vision training device according to an embodiment may extractaccommodation information specific to each user on the basis ofinformation derived by various methods of measuring the near point ofaccommodation position P5 and the far point of accommodation positionP6. The accommodation information may be extracted on the basis of thenear point of accommodation position P5 and the far point ofaccommodation position P6. The accommodation information may beindicated by values indicating the near point of accommodation positionP5 and the far point of accommodation position P6 themselves, may beindicated by a distance value of the display 130 or the lens 140 from areference position, or may be indicated by a diopter conversion value ofa corresponding position. The near point of accommodation position andthe far point of accommodation position information can be used as aparameter that is important for evaluating the vision of the user. Forexample, the near point of accommodation position can be used as anindex indicating how close a person can see clearly, that is, an indexof presbyopia, and the far point of accommodation position informationcan be used as an index indicating how far a person can see clearly,that is, an index of distance visual acuity. The status of the personalvision of the user is detected with this measurement mode as describedabove, and vision training in which the detected status of personalvision is considered is provided, so that the vision improvement effectcan be increased or maximized.

The vision training device according to an embodiment may include asensor module that detects whether the eye of the user is in theaccommodated state or the non-accommodated state by emitting infraredrays or light toward the eye of the user and receiving infrared rays orlight reflected from the eye of the user. The sensor module mayrepeatedly check if there is a change in an accommodation state of theeye of the user at set intervals. The sensor module may check if the eyeof the user transitions from the accommodated state to thenon-accommodated state, and transmit an accommodation state changeconfirmation signal to the control unit 190 when it is determined thatthe eye of the user transitions from the accommodated state to thenon-accommodated state. The sensor module may check if the eye of theuser transitions from the non-accommodated state to the accommodatedstate, and transmit the accommodation state change confirmation signalto the control unit 190 when it is determined that the eye of the usertransitions from the non-accommodated state to the accommodated state.The control unit 190 can set the near point of accommodation position P5and the far point of accommodation position P6 on the basis of theaccommodation state change confirmation signals.

The sensor module may employ a principle similar to an examinationprinciple of an auto refractor. The sensor module may include a lightoutput unit that outputs infrared light or light toward the eye of theuser, a light detecting unit that detects reflected light reflected fromthe eye of the user, and a refraction evaluating unit that calculatesthe focal length of the detected reflected light and calculates aposition at which infrared ray or light output toward the eye focus onthe eye using the focal length.

The control unit 190 sets an accommodation range AR on the basis of thenear point of accommodation P5 and the far point of accommodation P6decided in the measurement mode. The accommodation range AR correspondsto a range between the near point of accommodation position P5 and thefar point of accommodation position P6. Ranges (first non-accommodationrange (NAR1) and second non-accommodation range (NAR2)) outside theaccommodation range AR within the movable range MR of the display 130 orthe lens 140 are non-accommodation range.

FIG. 6 is a flowchart illustrating an exemplary training mode processfor a vision training device. The user presses the power button of theuser input unit 160 so that the vision training device is powered, wearsthe vision training device, and selects a training mode by pressing thetraining mode selection button of the user input unit 160 (S210).

If the training mode is selected by the user, the control unit 190 setsat least one training range within the movable range MR of the display130 (S220). The training range includes the accommodation range AR foreffective vision improvement. The control unit 190 may set a rangeincluding the accommodation range AR and at least a part of thenon-accommodation range (NAR1 and NAR2) within the movable range (MR) asthe training range.

In step S230, the display 130 or the lens 140 is continuously moved inthe set training range or is intermittently moved such that moving witha predetermined distance and waiting with a predetermined waiting timeare repeated (step S230). When the speed at which the display 130 or thelens 140 is moved and the waiting time after the movement are set inconsideration of the status of personal vision of the individual user,the vision improvement by the vision training can be more effectivelyachieved.

FIG. 7 is a flowchart illustrating an exemplary training mode processfor a vision training device, and FIG. 8 is a reference diagram fordescribing a training method according to an example of FIG. 7 .Referring to FIGS. 7 and 8 , to set the continuous moving speed or theintermittent waiting time in which the status of personal vision of theuser is reflected, in step S310, the control unit 190 controls thedisplay 130 or the lens 140 such that the display 130 or the lens 140 ispositioned at one of a plurality of measurement positions in thetraining range. For convenience of description, it is assumed that thedisplay 130 or the lens 140 is moved from a first measurement positionMP1 to a second measurement position MP2, but this is not limiting.

In step S320, the control unit 190 checks whether or not theaccommodation reflex confirmation signal is input from the user inputunit 160 or the sensor module 200. The accommodation reflex confirmationsignal is a signal indicating that the target image recognized by theuser becomes clear or that the eye of the user transitions to theaccommodated state.

If the user presses the user input unit 160 at the point at which thetarget image becomes clear at the second measurement position MP2, theaccommodation reflex confirmation signal is input. In a case in whichthe sensor module 200 is used, the sensor module 200 may repeatedlycheck the accommodation state of the eye of the user, and provides theaccommodation reflex confirmation signal to the control unit 190 whenthe eye of the user transitions to the accommodated state.

When the accommodation reflex confirmation signal is input, the controlunit 190 stores an accommodation time for the measurement position MP2(S330). The accommodation time may include a period of time until theaccommodation reflex confirmation signal is input after the display 130or the lens 140 starts to be moved toward the second measurementposition MP2. The accommodation time has a value that differs dependingon the status of personal vision of the user. The position of thedisplay 130 or the lens 140 in the vision training device may beconverted into a predetermined diopter value, and the converted dioptervalue may be provided to the user.

The accommodation time can be measured for each of a plurality ofmeasurement positions MP1 to MP10. It is desirable to measure theaccommodation time for each measurement position in accordance with themoving direction of the display 130 or the lens 140. This is because,although the measurement position is the same, the accommodation timemay be different depending on the position of the display 130 or thelens 140 before the target image is recognized. For example, when thedisplay 130 or the lens 140 enters the accommodation range AR from thenon-accommodation range NAR, the accommodation time at P5 is differentfrom that when the display 130 or the lens 140 enters thenon-accommodation range NAR from the accommodation range AR.

When the accommodation time is decided for each of the plurality ofmeasurement positions, the control unit 190 sets an intermittent movinginterval or the continuous moving speed V of the display 130 or the lens140 by reflecting the decided accommodation time (S340). Theintermittent moving interval includes an interval at which the display130 or the lens 140 moves and stops at corresponding positions, and thecontinuous moving speed V includes a moving speed of the display 130 orthe lens 140 passing a corresponding measurement position.

After the intermittent moving interval or the continuous moving speed Vis set, the control unit 190 performs control such that the display 130or the lens 140 stays or passes through a corresponding position at theset intermittent moving interval or the set moving speed at (S350).

The vision training is performed in consideration of the accommodationtime for each measurement position, and thus the customized visiontraining in which the accommodation time of the user for thecorresponding position is considered can be provided to the user.Therefore, it is possible to perform the vision training efficiently andto strengthen the ciliary muscle more effectively through the visiontraining.

In a range (for example, FAR) in which the accommodation time is short,a time taken for the eye of the user to accommodate to the target imageTI is short, and the accommodation power of the eye of the user is high.Therefore, the width of the training range is set to be relatively largewhen the accommodation time is short, and the width of the trainingrange is set to be relatively small when the accommodation time is long,and thus effective training can be performed without incurring anexcessive load on the user in the training process.

When the width of the training range and the continuous moving speed andthe intermittent moving interval of the display 130 or the lens 140within the training range are variably set in consideration of theaccommodation time of the user as described above, the visionimprovement effect the can be increased or maximized.

In an example, to set an effective training range on the basis of theabove-described information, the control unit 190 may set a near pointof accommodation position P3 and a far point of accommodation positionP4 within the accommodation range AR. The control unit 190 may set thenear point of accommodation position P3 and the far point ofaccommodation position P4 in consideration of both the width of theaccommodation range AR and a value related to the age of the user. Forexample, if the width of the accommodation range AR is large, a widefast accommodation range FAR can be set, and as the age increases, thewidth of the fast accommodation range FAR can be set to decrease. Arange between the nearest point of accommodation position P3 and the faradjustment reaction position P4 can be set as the fast accommodationrange FAR, and ranges other than the fast accommodation range FAR withinthe accommodation range AR can be set as slow accommodation ranges SAR1and SAR2. The fast accommodation range FAR can also be set by selectingtwo measurement points among the measurement points MP1 to MP10. Thefast accommodation range FAR includes a range in which the eye of theuser can perform the accommodation training comfortably and can beapplied to a virtual reality (VR) technique. In this case, the eyefatigue caused by a video reproduced in a VR game or the like is reducedduring the vision training, so that the user can enjoy a VR game or thelike while feeling as if the training were not performed.

In an example, the control unit 190 causes the display 130 or the lens140 to be positioned at either the near point of accommodation positionP5 or the far point of accommodation position P6. Hereinafter, for theconvenience of description, it is assumed that the display 130 or thelens 140 is moved to be positioned at the near point of accommodationposition P5, but that is not limiting.

The control unit 190 controls the movable unit 150 such that themeasurement operation in which the display 130 or the lens 140positioned at the near point of accommodation position P5 is moved inthe direction of the far position P2 by a predetermined distance andthen stays at the position for a preset waiting time is repeated. A slowaccommodation reflex confirmation signal is generated and input to thecontrol unit 190, for example, when the target image (TI) recognizedthrough the lens 140 does not become clear within a set waiting time(for example, 0.5 seconds), and so the user does not input theaccommodation reflex confirmation signal through the user input unit160. Alternatively, the slow accommodation reflex confirmation signal isgenerated and input to the control unit 190, for example, when thetarget image (TI) recognized through the lens 140 does not become clearwithin a set waiting time (for example, 0.5 seconds), and so the userinputs the slow accommodation reflex confirmation signal through theuser input unit 160 in accordance with a sound, a display, or the likeoutput from the control unit 190. When the control unit 190 receives theslow accommodation reflex confirmation signal, the control unit 190stops the measurement operation and sets the position of the display 130or the lens 140 at a time point at which the slow accommodation reflexconfirmation signal is received as the far point of accommodationposition P4. The near point of accommodation position P3 is set in asimilar manner. Accordingly, the fast accommodation range FAR includingthe range between the far point of accommodation position P4 and thenear point of accommodation position P3 is set.

In an example, the control unit 190 may automatically set the near pointof accommodation position P3 and the far point of accommodation positionP4. A middle point of a statistically average accommodation range at theuser's age may be set as the user reference position, or a position atwhich the user can see most comfortably when the display 130 or the lens140 is moved forward or backward at a predetermined speed within theline of sight range may be set as the user reference position inaccordance with the input from the user, and the control unit 190 maydecide positions which are at predetermined distance from the userreference position as the near point of accommodation position P3 andthe far point of accommodation position P4. The near point ofaccommodation position P3 and the far point of accommodation position P4may be set based on the age of the user.

The near slow accommodation range SAR1 and the far slow accommodationrange SAR2 may be decided on the basis of the first near point ofaccommodation position P3 and the first far point of accommodationposition P4. The near slow accommodation range SAR1 includes a rangebetween second first near point of accommodation position P5 and thefirst near point of accommodation position P3, and the far slowaccommodation range SAR2 includes a range between the second far pointof accommodation position P6 and the second far point of accommodationposition P4. Each of the slow accommodation ranges SAR1 and SAR2includes a range in which accommodation reserve power of the eye isreflected. In a case in which the vision training is performed in theslow accommodation ranges SAR1 and SAR2, it is possible to improve thevision of the user by expanding the accommodation reserve power and theaccommodation power of the user.

In a case in which the near slow accommodation range SAR1 and the farslow accommodation range SAR2 are set, it is desirable for the controlunit 190 to include at least a part of the near slow accommodation rangeSAR1 or the far slow accommodation range SAR2 in the training range. Thetraining range may include only the fast accommodation range FAR, but itis effective in improving the vision when a part of at least one of thenear slow accommodation range SAR1 and the far slow accommodation rangeSAR2 is included in the training range.

The training range may be set to a range between the near slowaccommodation range SAR1 and the far slow accommodation range SAR2, arange between the near slow accommodation range SAR1 and the fastaccommodation range FAR, or a range between the far slow accommodationrange SAR2 and the fast accommodation range FAR. Of course, the nearslow accommodation range (SAR1) or the far slow accommodation range(SAR2) may be used themselves or as a combination for the trainingrange. The user can select any one of such training ranges or acombination thereof. If there is no selection from the user, the controlunit 190 may arbitrarily set or select the training range.

When the training range is set, the control unit 190 performs controlsuch that the display 130 or the lens 140 is moved within the trainingrange. The control unit 190 can cause the display 130 or the lens 140 tobe moved continuously or intermittently. The control unit 190 maycontrol such that the display 130 or the lens 140 performs continuousreciprocating movement within the training range or repeatedly performsmovement in which the display 130 or the lens 140 is moved by apredetermined distance within the set training range and then stays fora set waiting time. Such movement of the display 130 or the lens 140along the fixation axis produces the similar effect as when the dioptervalue of the lens 140 or the refractive index is changed.

The image size of the target image TI may vary depending on a distance.For example, a setting may be performed so that as the display 130 orlens 140 approaches the eyepiece unit 124, the image size graduallydecreases, whereas as the display 130 or lens 140 moves towards the farposition P2, the image size gradually increases. Accordingly, it ispossible to measure the accommodation power or the near point ofaccommodation position P5 and the far point of accommodation position P6more accurately and perform effective training.

With such training, the ciliary muscle of the user contracts or relaxesand accommodates to the change in the focal length for the target image(TI) changing with the movement of the display 130 or the lens 140, sothat the ciliary muscle is strengthened.

Upon completion of the vision training, the vision training device endsthe training and stores training data in the memory 180. The trainingdata includes information related to a time until one cycle of trainingends, the training mode, and the training condition. The training datais stored for each user, and the stored training data is analyzed toconfirm a degree of improvement of the vision according to the training.Therefore, the user can check the degree of improvement of the visionand effectively set up a future training plan and a training direction.For example, the user can comprehend whether the vision training isperformed in the SAR range or the FAR range depending on the status ofthe personal vision of the user such as the accommodation speed or thedistance visual acuity.

The vision training device can measure the near point of accommodationposition P5 and the far point of accommodation position P6 correspondingto the current status of personal vision of the user and sets thetraining range on the basis of the near point of accommodation positionP5 and the far point of accommodation position P6, and thus high visionimprovement can be provided.

FIG. 9 is a reference view for describing the training process accordingto the movement of the lens 140. As can be seen in FIG. 9 , the visiontraining device changes the focal length between the target image (TI)and the eye by moving the display 130 and/or the lens 140 and thusstrengthens the ciliary muscle associated with vision. The descriptionof the measurement mode and the training mode based on the movement ofthe display 130 described above is similarly applied to the visiontraining based on the movement of the lens 140. As the lens 140 ismoved, the first near point of accommodation position P3, the first farpoint of accommodation position P4, the second near point ofaccommodation position P5, and the second far point of accommodationposition P6 can be measured on the basis of the position of the lens140, the fast accommodation range FAR, the near slow accommodation rangeSAR1, and the far slow accommodation range SAR2 can be set on the basisof the positions, and then the vision training can be performed.

The movement of the display 130 and the movement of the lens 140 mayboth be performed to change the focal distance between the target imageTI and the eye. In some examples, the display 130 and the lens 140 maybe moved together to change the focal length between the target image TIand the eye and strengthen the ciliary muscle associated with thevision.

FIG. 10 is an explanatory diagram schematically illustrating anexemplary vision training device. As illustrated in FIG. 10 , the visiontraining device may include a plurality of lenses along the fixationaxis. The vision training device may include a second lens 145 arrangedbetween the eyepiece unit 124 and the lens 140 along the fixation axis.In a case in which a plurality of lenses are installed, the visiontraining can be performed by changing the refractive power variouslyrather than in a case in which a single lens is installed. The secondlens 145 may be arranged between the lens 140 and the display 130. Theposition of the second lens 145 can be fixed or variable. The movableunit 150 may selectively move at least one of the lens 140 and thesecond lens 145. A piezo actuator, a voice coil motor (VCM) actuator, oran encoder actuator may be employed as the movable unit 150. The movableunit 150 may include a second movable unit for moving the second lens145, and any of a piezo actuator, a VCM actuator, and an encoderactuator may be employed as the second movable unit 150. In addition tothe second lens 145, one or more lenses that are fixed or movable andadditionally affect the adjustment of the focal length may be arranged.

The image size of the target image (TI) may vary depending on theposition of the display 130. For example, it is desirable that as thedisplay 130 or the lens 140 approaches the eyepiece unit 124, the imagesize of the target image TI increases, and as the display 130 or thelens 140 gets away from the eyepiece unit 124, the image size of thetarget image TI decreases. Accordingly, accurate accommodation powermeasurement and the effective training can be performed.

It will be appreciated that the target image can be moved up, down,left, or right. Accordingly, it is possible to cause the muscles of theeyes to exercise in various methods.

While various embodiments in accordance with the disclosed principleshave been described above, it should be understood that they have beenpresented by way of example only, and are not limiting.

Furthermore, the above advantages and features are provided in describedembodiments, but shall not limit the application of such issued claimsto processes and structures accomplishing any or all of the aboveadvantages.

Although the invention(s) is/are described herein with reference tospecific embodiments, various modifications and changes can be madewithout departing from the scope of the disclosure. Accordingly, thespecification and figures are to be regarded in an illustrative ratherthan a restrictive sense, and all such modifications are intended to beincluded within the scope of the present disclosure. Any benefits,advantages, or solutions to problems that are described herein withregard to specific embodiments are not intended to be construed as acritical, required, or essential feature or element of any or all theclaims.

Unless stated otherwise, terms such as “first” and “second” are used toarbitrarily distinguish between the elements such terms describe. Thus,these terms are not necessarily intended to indicate temporal or otherprioritization of such elements. The terms “coupled” or “operablycoupled” are defined as connected, although not necessarily directly,and not necessarily mechanically. The terms “a” and “an” are defined asone or more unless stated otherwise. The terms “comprise” (and any formof comprise, such as “comprises” and “comprising”), “have” (and any formof have, such as “has” and “having”), “include” (and any form ofinclude, such as “includes” and “including”) and “contain” (and any formof contain, such as “contains” and “containing”) are open-ended linkingverbs. As a result, a system, device, or apparatus that “comprises,”“has,” “includes” or “contains” one or more elements possesses those oneor more elements but is not limited to possessing only those one or moreelements. Similarly, a method or process that “comprises,” “has,”“includes” or “contains” one or more operations possesses those one ormore operations but is not limited to possessing only those one or moreoperations.

The invention claimed is:
 1. A vision training device, comprising: ahousing having an eyepiece unit configured to be viewed by an eye of auser; a display configured to display a target image in front of afixation axis of the user; a lens disposed between the eyepiece unit andthe display; an actuator configured to move at least one of the displayor the lens along the fixation axis; and a control unit configured to:(1) set a training range within a movable range of the display and thelens, (2) control the actuator such that at least one of the display orthe lens is moved within the training range, (3) set an accommodationrange corresponding to a range between a near point of accommodationposition and a far point of accommodation position and within themovable range, (4) determine an accommodation speed within theaccommodation range based on data derived from at least one of a userinput unit or a sensor, and (5) determine a training speed in thetraining range based on the determined accommodation speed; wherein: (1)the accommodation speed is based on an accommodation time; and (2) theaccommodation time is based on a time from when the display or lens ismoved to a measurement point and a time when the user's eye transitionsfrom a non-accommodated state to an accommodated state.
 2. The visiontraining device according to claim 1, further comprising the user inputunit, wherein the control unit is configured to set the near point ofaccommodation position and the far point of accommodation position inresponse to signals from the user input unit.
 3. The vision trainingdevice according to claim 1, further comprising the sensor configuredto: (a) determine if the eye of the user transitions from theaccommodated state to the non-accommodated state or transitions from thenon-accommodated state to the accommodated state, and (b) generateaccommodation state change confirmation signals, wherein the controlunit is configured to set the near point of accommodation position andthe far point of accommodation position based on the accommodation statechange confirmation signals.
 4. The vision training device according toclaim 1, wherein the control unit is configured to: determine the nearpoint of accommodation position and the far point of accommodationposition based on the data derived from the user input unit or thesensor, and differentiate a beginning and an end of a fast accommodationrange from the accommodation range based on the data derived from theuser input unit or the sensor; wherein both the beginning and the end ofthe fast accommodation range are between the near point of accommodationposition and the far point of accommodation position.
 5. The visiontraining device according to claim 4, wherein the control unit isconfigured to set the training range based on the differentiatedbeginning and end of the fast accommodation range.
 6. The visiontraining device according to claim 1, further comprising a second lensdisposed between the lens and the display along the fixation axis orbetween the lens and the eyepiece unit.
 7. The vision training deviceaccording to claim 6, wherein the actuator is configured to move atleast one of the lens or the second lens.
 8. The vision training deviceaccording to claim 6, further comprising a second actuator configured tomove the second lens along the fixation axis.
 9. The vision trainingdevice according to claim 1, wherein the actuator includes one or moreof a piezo actuator, a voice coil motor (VCM) actuator, or an encoderactuator.
 10. The vision training device according to claim 1, whereinthe display is configured such that an image size of the target imagevaries depending on a position of the display.
 11. A vision improvementmethod, comprising: providing a housing having an eyepiece unitconfigured to be viewed by an eye of a user, a display configured todisplay a target image in front of a fixation axis of the user, a lensdisposed between the eyepiece unit and the display, and an actuatorconfigured to move at least one of the display or the lens along thefixation axis; determining a training range within a movable range ofthe display and the lens; and determining a near point of accommodationposition and a far point of accommodation position; determining anaccommodation range corresponding to a range between the near point ofaccommodation position and the far point of accommodation position andwithin the movable range; distinguishing between a fast accommodationrange within the accommodation range and a slow accommodation rangewithin the accommodation range; determining an accommodation speedwithin the accommodation range based on data derived from at least oneof a user input unit or a sensor; determining a training speed in thetraining range based on the determined accommodation speed; and movingat least one of the display or the lens within the training range. 12.The vision improvement method according to claim 11, further comprisingdetermining the near point of accommodation position and the far pointof accommodation position in response to signals from the user inputunit.
 13. The vision improvement method according to claim 11, wherein:the sensor is configured to: (a) determine if the eye of the usertransitions from an accommodated state to a non-accommodated state ortransitions from the non-accommodated state to the accommodated state,and (b) generate accommodation state change confirmation signals; themethod further comprises determining the near point of accommodationposition and the far point of accommodation position based on theaccommodation state change confirmation signals.
 14. The visionimprovement method according to claim 11, further comprising moving asecond lens along the fixation axis, the second lens disposed betweenthe lens and the display or between the lens and the eyepiece unit. 15.The vision improvement method according to claim 11, wherein an imagesize of the target image varies depending on a position of the display.16. A vision training device, comprising: a housing having an eyepieceunit configured to be viewed by an eye of a user; a display configuredto display a target image in front of a fixation axis of the user; alens disposed between the eyepiece unit and the display; an actuatorconfigured to move at least one of the display or the lens along thefixation axis; and a control unit configured to: (1) set a trainingrange within a movable range of the display and the lens, (2) controlthe actuator such that at least one of the display or the lens is movedwithin the training range, (3) determine a near point of accommodationposition and a far point of accommodation position based on data derivedfrom at least one of a user input unit or a sensor; (4) set anaccommodation range corresponding to a range between the near point ofaccommodation position and the far point of accommodation position andwithin the movable range, (5) determine an accommodation speed withinthe accommodation range based on the data derived from at least one ofthe user input unit or the sensor, (6) determine a training speed in thetraining range based on the determined accommodation speed; and (7)differentiate a beginning and an end of a fast accommodation range fromthe accommodation range based on the data derived from the user inputunit or the sensor; wherein both the beginning and the end of the fastaccommodation range are between the near point of accommodation positionand the far point of accommodation position.
 17. The vision trainingdevice according to claim 16, wherein the control unit is configured toset the training range based on the differentiated beginning and end ofthe fast accommodation range.
 18. The vision training device accordingto claim 17, further comprising the user input unit, wherein the controlunit is configured to set the near point of accommodation position andthe far point of accommodation position in response to signals from theuser input unit.
 19. The vision training device according to claim 17,further comprising the sensor configured to: (a) determine if the eye ofthe user transitions from an accommodated state to a non-accommodatedstate or transitions from the non-accommodated state to the accommodatedstate, and (b) generate accommodation state change confirmation signals,wherein the control unit is configured to set the near point ofaccommodation position and the far point of accommodation position basedon the accommodation state change confirmation signals.
 20. The visiontraining device according to claim 17, wherein the actuator includes oneor more of a piezo actuator, a voice coil motor (VCM) actuator, or anencoder actuator.